I think Below KB explains the behavior, KB: 119314
Informatica supports users with valid maintenance agreements, who run Informatica platform versions 9 and 10 products on Oracle Linux provided that a corresponding version of RHEL is also supported by Informatica for those products, and provided that a strictly Red Hat-compatible kernel is being used (see below).
Check the appropriate Informatica Platform Availability Matrix (PAM) to identify which versions of RHEL are supported for any given Informatica product.
Oracle Linux version should be supported as long as the corresponding kernel version of RHEL is supported by Informatica.
One additional side note: the "normal" kernel provided by Oracle can be certified to run with Informatica software, but NEVER use the Unbreakable Kernel. Quite a bit of the innermost kernel parts have been changed by Oracle for the Unbreakable Kernel, and this doesn't support Informatica software. Always run on the standard kernel.